Hank is not gonna change sides or bitch out and die UNLESS he slips all his cards to Walt and let him get that manipulation psyche destruction thing going on. But Hank becoming a little bitch for the whole season would be less intense than a real face off between the two.
A person in that situation (majestically fucked over) can either act or react. Rage is an option, as is total catatonic dismissal of all emotions. Both would make it obvious that he found out. Instead, as happens often in movies, Hank might go to full Player mode, walk back to the pool like nothing happened and eventually drive back home to plan the next step without a flinch, retaining the element of surprize for himself. (relative surprize, as walt most def knows precisely what to say and how to act if Hank confronts him man to man, not as a DEA official)
Maybe Hank could arrest Skyler. Someone is most likely going to get all the money she's stashed.